Cappy - 31-3-2003 at 20:32
Although not street legal, N2O is sometimes used to increase rate that fuel can be burned by supplying an additional source of oxygen. Although N2O
contains a higher percentage of oxygen than air(33% vs. 21%), pure oxygen could be used. Oxygen gas contains twice as many oxygen atoms per mole of
gas as N2O. Both gasses can be easily condensed for high density in storage. Both cool the intake charge significantly by evaporating, further
increasing oxygen density. However, N2O is used and not O2.
I'm assuming that N2O has some practical advatage of O2, otherwise smart people would have been using O2 by now. Does N2O require less energy to
free oxygen atoms for combustion? Does the formation of triple-bonded N2 release greater energy? Is N2O cheaper or safer to bottle and use?
[Edited on 4/1/2003 by Cappy]
madscientist - 31-3-2003 at 21:30
My guess would be that it has to do with the highly exothermic formation of N<sub>2</sub>.
a_bab - 31-3-2003 at 21:31
QUOTE: "Both gasses can be easily condensed for high density in storage"
Well, it's not true. While the N2O can be easily liquified, O2 cannot. This is due to the critical temperature of the oxygen.
vulture - 1-4-2003 at 13:29
You can't use pure oxygen in an engine.
This would cause to rapid ignition and flame front dispersion which would cause the famous "rattling" or "bumping" of an engine,
because the piston head does not follow quickly enough because of it's inertia.
Secondly, the pure oxygen would severely corrode the piston in a very short time.
The N<sub>2</sub> acts as a reaction mediator because of it's relative inertia.
N<sub>2</sub> formation does not contribute to the reaction enthalpy as it's formation enthalpy is zero. I know that the bondenergy
is huge, but you may not include this when calculating enthalpy.
If you would want to, you would have to calculate with the bond breaking and formation energies of every bond that participates in
the reaction.
[Edited on 1-4-2003 by vulture]
Theoretic - 24-6-2003 at 07:45
Quote:
"I'm assuming that N2O has some practical advatage of O2, otherwise smart people would have been using O2 by now. Does N2O require less
energy to free oxygen atoms for combustion? Does the formation of triple-bonded N2 release greater energy? Is N2O cheaper or safer to bottle and
use?"
Correct. All of those contribute.